SUSTAINED RELEASE MATRIX DRUG DELIVERY SYSTEM: AN OVERVIEW

Oral delivery of drugs is the most preferable route of drug delivery due to the ease of administration, patient compliance and flexibility in formulation, etc. Sustained release constitutes are the dosage form that provides medication over an extended time or denotes that the system is able to provide some actual therapeutic control whether this is of a temporal nature, spatial nature or both. The objective of the study was to explore the necessity, advantages and various techniques of extended release matrix tablet to get a constant drug delivery rate and reproducible kinetics for advance delivery. Matrix tablets are the type of controlled drug delivery systems, which release the drug in continuous manner by dissolution controlled as well as diffusion controlled mechanisms. To control the release of the drugs, which are having different solubility properties, the drug is dispersed in swellable hydrophilic substances, an insoluble matrix of rigid non swellable hydrophobic materials or plastic materials. Matrix tablets can be formulated by either direct compression or wet granulation method by using a variety of hydrophilic or hydrophobic polymers. The extended release matrix tablets can assure better patient compliance through reduction in total dose and dosage regimen, which can be great help to treat chronic diseases. This review highlights the types of matrices, mechanisms involved and evaluation studies.